#深复制
my_foods=['pizza','falafel','carrot cake']
friend_foods=my_foods[:]
print("My favourite foods are :")
print(my_foods)
print("\nMy friend's favourite foods are :")
print(friend_foods)

my_foods.append('cannoli')
friend_foods.append("ice cream")
print(my_foods)
print(friend_foods)

#浅复制
friend_foods=my_foods
my_foods.append("cannoli")
friend_foods.append("ice cream")
print("My favourite foods are:")
print(my_foods)
print("\nMy friend's favourite foods are:")
print(friend_foods)